Recently, the patterns to be inspected, each comprising circuit patterns or wiring patterns formed on, for example, the semiconductor wafer, the TFT liquid crystal substrate, the thin film multi-layer substrate and the printed board have been adapted to be further micro-structured in response to the needs for high density integration. Since the circuit patterns or the wiring patterns are further micro-structured along with high density integration, a defect which should be detected becomes smaller or finer. Detection of such micro fine defects has been an extremely important subject in determination of an integrity of the circuit patterns or the wiring patterns in manufacturing of the circuit patterns or the wiring patterns.
However, the above-described micro structure has been further advanced and detection of micro fine defects of the patterns to be inspected such as the circuit patterns or the wiring patterns has reached the limit of resolution of the imaging optical system, and therefore essential improvement of the resolution has been demanded.
A prior art apparatus for essentially improving the resolution is disclosed in Japanese Patent Laid-Open No. Hei 5-160002. In this document, there is disclosed a pattern inspection apparatus which comprises an illumination arrangement for providing an annular-looped diffusion illumination formed with arrays of a plurality of virtual spot light sources for micro fine circuit patterns which is formed on a mask, through light source space filters, a light receiving arrangement having an optical pupil which sufficiently introduces a diffraction light from the micro fine pattern, which passes through or reflected from a mask which is almost uniformly diffusion-illuminated by the illumination arrangement and has imaging space filters for shutting off at least part of 0th order diffraction light or low order diffraction light of this introduced light, to obtain image signals by receiving the circuit pattern imaged through the optical pupil, and a comparison arrangement for comparing the image signals obtained by the light receiving arrangement with mask pattern data or wafer pattern data or data from a transfer simulator to inspect the pattern. In this document, there is also disclosed a method for controlling a shape of a light source space filter and an imaging space filter in accordance with the pattern shape data.
However, there has been a problem that, though, in the above-described prior art with respect to detection of a defect of the micro fine pattern. That is, although a defect of the micro fine pattern is detected by applying the annular-looped diffusion illumination to the micro fine pattern on the object to be inspected and sufficiently introducing the diffraction light from the micro fine pattern into the opening (pupil) of the objective lens to obtain high resolution image signals, full consideration has not been taken for the point that a micro fine defect should be detected with high reliability in response to various micro fine patterns existing on the object to be inspected.
Further, full consideration has also not been given for manufacturing semiconductor substrates having micro fine patterns such as a semiconductor wafer, a TFT liquid crystal substrate, a thin film multi-layer substrate and a printed board with reduced defects and high yield rate.